Fabric treatment



Patented Nov. 12, 1946 FABRIC TREATMENT Cyril M. Croft and William J. Cramer, Jra,

Cumberland, Md., assignors to Celanese Corporation of America, a corporation of Delaware No Drawing. Application May 7, 1942 Serial No. 442,070

14 Claims.

This invention relates to the preparation of crepe fabrics, and more particularly to the preparation of crepe fabrics containing organic derivatives of cellulose.

Textile fabrics exhibiting crepe effects have long been obtained by employing in their construction highly twisted yarns, hereinafter referredto as crepe yarns or crepe threads, made of natural silk in the gummed state, the crepe effects appearing when the gum is subsequently removed by scouring or like treatment. The production of crepe effects by the employment of highly twisted crepe threads made of cellulose acetate or other organic derivatives of cellulose is however accomplished with considerable dim-- culty.

An object of our invention is the economic production of crepe fabrics containing organic derivative of cellulose yarns or threads.

A further object of our invention is the production of improved crepe effects upon fabrics containing crepe yarns or threads of an organic derivative of cellulose which shrink and buckle when treated in a creping bath.

A still further object of our invention is to minimize the appearance of exposure marks on dyed fabrics containing said crepe yarns or threads while at the same time producing the desired crepe effects by treatment in a creping bath.

Other objects of our invention will appear from the following detailed description.

It has previously been found that if yarns of cellulose acetate or other organic derivativeof cellulose have a high twist imparted thereto in the presence of hot aqueous media, such as steam or hot water, they produce crepe effects in fabrics containing them when the fabrics are given treatment in hot aqueous baths. It has also been found that if certain scouring or penetrating agents, such as soaps, pine oil, tetralin, etc., are incorporated in the creping or boil-off bath, the desired crepe effect is enhanced and is achieved in a relatively short period of time. When fabrics which have been treated with crepe baths containing such crepe enhancing agents are dyed, however, it has been observed that the resulting crepe fabrics take the dyestuffs some-what unevenly. This undesirable effect is particularly noticeable in the case of fabrics which have been stored for even a limited time prior to the creping operation, especially at those portions of the fabric which have been exposed to the air during storage. The use of scouring and penetrating agents in the creping bath appears to aggravate this condition. As a result, the appearance of such unevenly dyed areas, or exposure marks, as they are called, is a serious problem and causes substantial portions of the dyed crepe fabrics to be degraded with respect to commercial value.

We have now discovered, however, that the appearance of exposure marks on dyed crepe fabrics may be minimized or entirely eliminated. These beneficial results may be achieved if an aqueous creping or boil-01f bath containing a small amount of a lower aliphatic acid is employed in place of the creping baths heretofore employed.-

Lower aliphatic acids such as'formic, acetic, propionic, and butyric acid may be employed satisfactorily in accordance with our invention. The concentration of the acid in the creping bath may be varied. Generally, creping baths containing the acid in a'concentration of from 1% to 5% by Volume are suitable. In the case where fabrics containing crepe yarns of cellulose acetate are'treated with an aqueous creping bath containing acetic acid, we preferably employ an aqueous bath containing the acetic acid in a concentration of about 2% by volume. The creping bath may be prepared by adding glacial acetic acid, or other acid, to the water in the desired volumetric proportion.

In carrying out our invention, the fabric may be treated in the boil-off bath in the open width or in skein form. The bath may be maintained at temperatures ranging from to 99 C. and the desired crepe effect in the fabric may be obtained by maintaining the fabric in the bath for from 3 to 50 minutes. Preferably, when treating fabrics containing crepe yarns of cellulose acetate with an aqueous creping bath containing a small amount of acetic acid, We enter the fabric in skein form in. the bath heated to about C. and gradually bring the temperature up to about 99 0., usually in from. 10 to 30 minutes. The fabric is held in the bath, which is maintained at this temperature, until the crepe is fully developed. The additional period necessary for the full development of the crepe may be from 3 to 30minutes,'and is preferably 10 or more minutes.

As stated above, the fabric treated by this invention contains filaments, yarns or thread which which have been twisted in the presence of hot aqueous fluids such as steam or hot Water; for instance, in the manner described in U. S. Patents Nos. 2,088,628 and 2,089,191. This twisting may be effected on a device of the kind in which the thread is drawn off over the head of a rotating package through a guide fixed substantially in line with the axis of rotation of the package and is thereafter wound on a bobbin or the like, the thread being passed through hot aqueous fluid on its way from the guide to the bobbin. In this way the yarn is subjected to the action of the hot aqueous fluid during the actual application of twist. The twisting spindle, the guide fixed in line with the axis of the spindle and the device for'applying the hot aqueous fluid to the filaments, yarns or threads should be so arranged that the twisting resulting from the rotation of the package is at least partially inserted while the thread is in contact with the hot aqueous fluid.

The crepe twisting may be applied in a single stage. If desired, however, the crepe twist may be applied in two or more stages, at least the final stage of twisting being effected while treating the thread with hot aqueous fluid, as described in U. S. Patent No. 2,088,587.

The total twist applied may vary within wide limits, and the crepe figure in the fabric may be regulated according to requirements. The total twist desirable in any particular case depends upon a number of factors, including the precise effects required, the number of filaments and the denier of the thread. The number of turns to be employed may be from 55 to 90 turns per inch.

The highly twisted crepe threads may be incorporated in the fabrics in various ways. Thus, for example, the weft may be wholly or partially composed of such threads while the Warp may be composed of other threads. Or, in some instances, both the warp and the weft may be composed of said highly twisted crepe threads. Valuable fabrics may be produced by employing warp threads of relatively low twist and in the weft employing crepe threads havin both a left hand twist and crepe threads having a right hand twist, pairs of threads of left hand twist alternating with pairs of threads of right hand twist.

If desired, the cellulose acetate crepe threads may be associated in the fabrics with highly twisted crepe threads of other materials, e. g. of natural silk or regenerated cellulose, or with highly twisted threads produced by other processes. Where the fabrics contain threads of low twist these may be wholly of cellulose acetate or wholly or in part of other materials, e. g. natural silk or regenerated cellulose. The cellulose acetate crepe threads may be doubled with ordinary cellulose acetate yarns or yarns of other materials prior to incorporation in the fabric.

In carrying our invention into effect, fabrics containing filaments, yarns or threads of any organic derivative of cellulose may be employed in the manufacture of the new crepe threads. For example, filaments, yarns or threads containing cellulose esters such as cellulose acetate, cellulose propionate, cellulose butyrate, mixed esters, such as cellulose acetate-propionate and cellulose ethers, such as ethyl cellulose and benzyl cellulose may be employed. The invention, however, is of especial value in the production of crepe fabrics containing yarns or threads of cellulose acetate and will accordingly be described in connection therewith.

Fabrics containing highly twisted crepe threads of an organic derivative of cellulose may now be stored indefinitely with little or no danger that upon subsequent creping and dyeing the fabric will be of limited commercial value due to the appearance of exposure marks. By developing the crepe of the fabric in an aqueous creping bath containing a small amount of a lower aliphatic acid, the danger of exposure marks appearing when the fabric is dyed is greatly minimized, and,

from a commercial point of view, may be considered to be substantially eliminated.

In order further to illustrate our invention but without being limited thereto the following examples are given:

Example I A fabric having a warp of ends per inch of cellulose acetate yarn of 75 denier having 28 turns per inch, and a weft of '70 picks per inch of cellulose acetate yarn of denier having 77 turns per inch, which twist has been inserted in the presence of steam, is entered in skein form into an aqueous boil-off bath containing 2% by volume of glacial acetic acid. The bath is at a temperature of 90 C. when the fabric is entered, and is brought up to 99 C. during the course of 30 minutes. The bath is held at this temperature for another 30 minutes to obtain a full crepe effect.

The resulting crepe fabric is dyed a navy shade with a dye bath of suitable composition containing dyestuffs having an aflinity for cellulose acetate materials. Upon examination, after a suitable finishing treatment, the fabric is found to be entirely free of those unevenly dyed areas which are commonly termed exposure marks. When a length of fabric of the same age is creped in a bath of the usual composition and then dyed it is observed that about 30% of the fabric is degraded due to the presence of exposure marks.

Example II A fabric of a construction similar to that employed in Example I is entered into an aqueous boil-ofl bath containing 4% by volume of glacial acetic acid. The bath is at a temperature of 60 C. when the fabric is entered and is brought up to 90 C. in 45 minutes. To complete the development of the crepe, the fabric is held in the bath at this temperature for 10 minutes.

The crepe fabric obtained by this treatment, when dyed, is found to be free of exposure marks.

It is to be understood that the foregoing detailed description is merely given by way of illustration and that many variations may be made therein without departing from the spirit of our invention.

It is also to be understood that the expression creping bath, as employed in the claims, is to be construed as meaning a creping or boiloif bath containin scouring or penetrating agents, such as soaps, pine oil, tetralin, etc.

Having described our invention, what we desire to secure by Letters Patent is:

1. Process for the production of crepe efiects on fabrics comprising yarns containing filaments of an organic derivative of cellulose which have been crepe twisted while being subjected to the action of a hot aqueous fluid, which comprises treating said fabrics with a hot aqueous creping bath to which has been added a small amount of a lower aliphatic acid.

2. Process for the production of crepe effects on fabrics comprising yarns containing filaments of cellulose acetate which have been crepe twisted while being subjected to the action of a hot aqueous fluid, which comprises treating said fabrics with a hot aqueous creping bath to which has been added a small amount of a lower aliphatic acid.

3. Process for the production of crepe effects on fabrics comprising yarns containing filaments of cellulose acetate which have been crepe twisted While being subjected to the action of a hot aqueous fluid, which comprises treating said fabrics with a hot aqueous creping bath to which has been added a small amount of acetic acid.

4. Process for the production of crepe efiects on fabrics comprising yarns containing filaments of cellulose acetate which have been crepe twisted while being subjected to the action of a hot aqueous fluid, which comprises treating said fabrics with a hot aqueous creping bath to which has been added from 1 to 5% by volume of acetic acid.

5. Process for the production of crepe effects on fabrics comprising yarns containing filaments of cellulose acetate which have been crepe twisted while being subjected to the action of a hot aqueous fluid, which comprises treating said fabrics with a hot aqueous creping bath to which has been added from 1 to 5% by volume of acetic acid for from 3 to 50 minutes.

6. Process for the production of crepe effects on fabrics comprising yarns containing filaments of cellulose acetate which have been crepe twisted while being subjected to the action of a hot aqueous fluid, which comprises entering said fabrics into a hot aqueous creping bath to which has been added 2% by volume of acetic acid maintained at about 90 C., gradually raising the temperature of said bath to about 99 C. over the course of minutes and maintaining the fabric in said bath until the desired crepe effect is obtained.

7. Process for the production of crepe effects on fabrics comprising yarns containing filaments of cellulose acetate which have been crepe twisted while being subjected to the action of a hot aqueous fluid, which comprises entering said fabrics into a hot aqueous creping bath to which has been added 4% by volume of acetic acid maintained at about 60 C. gradually raising the temperature of said bath to about 90 C. over the course of 45 minutes and maintaining the fabric in said bath until the desired crepe effect is obtained.

8. Process for the coloration of fabrics comprising yarns containing filaments of an organic derivative of cellulose which have been crepe twisted while being subjected to the action of a hot aqueous fluid, which comprises treating said fabrics with a hot aqueous creping bath to which I has been added a small amount of a lower aliphatic acid until the desired crepe effect is obtained, and then dyeing said fabrics with a dye bath containing dyestuffs having an afiinity for the organic derivative of cellulose materials, whereby there are obtained dyed fabrics exhibiting substantially no exposure marks.

9. Process for the coloration of fabrics comprising yarns containing filaments of cellulose acetate which have been crepe twisted while being subjected to the action of a hot aqueous fluid, which comprises treating said fabrics with a hot aqueous creping bath to which has been added a small amount of a lower aliphatic acid until the desired crepe effect is obtained and then dyeing said fabrics with a dye bath containing dyestuffs having an aflinity for the cellulose ace-' tate material, whereby there are obtained dyed fabrics exhibiting substantially no exposure marks.

10. Process for the coloration of fabrics comprising yarns containing filaments of cellulose acetate which have been crepe twisted while being subjected to the action of a hot aqueous fluid, which comprises treating said fabrics with a hot aqueous creping bath to which has been added a small amount of acetic acid until the desired crepe effect is obtained and then dyeing said fabrics with a dye .bath containing dyestuffs having an affinity for the cellulose acetate material, whereby there are obtained dyed fabrics exhibiting substantially no exposure marks.

11. Process for the coloration of fabrics comprising yarns containing filaments of cellulose acetate which have been crepe twisted while being subjected to the action of a hot aqueous fluid, which comprises treating said fabrics with a hot aqueous creping bath to which has been added from 1 to 5% by volume of acetic acid until the desired crepe effect is obtained and then dyeing said fabrics with a dye bath containing dyestuffs having an affinity for the cellulose acetate material, whereby there are obtained dyed fabrics exhibiting substantially no exposure marks.

12. Process for the coloration of fabrics comprising yarns containing filaments of cellulose acetate which have been crepe twisted while being subjected to the action of a hot aqueous fluid, which comprises treating said fabrics with a hot aqueous creping bath to which has been added from 1 to 5% by volume of acetic acid for from 3 to 50 minutes and then dyeing said fabrics with a dye bath containing dyestuffs having an affinity for the cellulose acetate material, whereby there are obtained dyed fabrics exhibiting substantially no exposure marks.

13. Process for the coloration of fabrics comprising yarns containing filaments of cellulose acetate which have been crepe twisted while being subjected to the action of a hot aqueous fluid, which comprises entering said fabrics into a hot aqueous creping bath to which has been added 2%. by volume of acetic acid maintained at about C., gradually raising the temperature of said bath to about 99 C. over the course of 30 minutes and maintaining the fabric in said bath until the desired crepe effect is obtained, and then dyeing said fabrics with a dye bath containing dyestuffs having an affinity for the cellulose acetate material, whereby there are obtained dyed fabrics exhibiting substantially no exposure marks.

.14. Process for the coloration of fabrics comprising yarns containing. filaments of cellulose acetate which have been crepe twisted while being subjected to the action of a hot aqueous fluid, which comprises entering said fabrics into a hot aqueous creping bath to which has been added 4% by volume of acetic acid maintained at about 60 C., gradually raising the temperature of said bath to about 90 C. over the course of 45 minutes and maintaining the fabric in said bath until the desired crepe effect is obtained,

and then dyeing said fabrics with a dye bath.

containing dyestuffs having an affinity for the cellulose acetate material, whereby there are obtained dyed fabrics exhibiting substantially no exposure marks.

CYRLIL M. CROFT. WILLIAM J. CRAMER, JR. 

